Typewriting machine



Oct. 31, 1933. I G G, 1,932,620

TYPEWRITING MACHINE Filed Dec. 1, 1932 4" 5 gr i g INVENTOR ATTORNEY Patented Get. 31, 1933 J TYPEWRITING. MACHINE George G. Going, Glenbrook, Conn., assignor to Remington Rand Inc., New York, N. Y., a corporaticn of Delaware Application December 1,

I 11 Claims.

My invention relates to typewriting and like machines, and more particularly to carriage escapement mechanism therefor.

The main object of my invention, generally stated, is to provide improved carriage escapement mechanism which is substantially noiseless in its operation without interfering with the accurate spacing of the carriage at letter space intervals.

More specifically stated, one of the main objects of my invention is to provide improved carriage escapement mechanism in which the shocks or impacts incidental to the step-by-step letter space movements of the carriage are absorbed, counteracted or dissipated before they reach the frame of the machine and thus effect a substantially noiseless feed of the carriage and without interfering with accurate spacing of the carriage at letter-space intervais or with an accurate spacing of the printed characters.

A further object of my invention is to provide mechanism of the character indicated that may be readily combined with standard escapement mechanisms without materially modifying the existing structural features thereof.

To the above and other ends which will hereinafter my invention consists in the features of construction, arrangements of parts and combinaticns of devices set forth in the following descriptlon and particularly pointed out in the appended claims. I

,In the accompanying drawing wherein like ference characters indicate corresponding parts the different views Fig. 1 is an enlarged, detail, fragmentary, rear elevation, with in section, of the escapement mechanisn of a typewriting machine together with some of the associated parts.

Fig. 2 is a transverse, horizontal, sectional view of the same taken on the line 22 of Fig. l and locking in the direction of the arrows at said line.

3 is an enlarged, detail, fragmentary, vertical, secti 1 view taken on the line 3-3 of Fig, 2 and locking in the direction of the arrows at said line.

Fig. l is an enlarged, detail, vertical, sectional view taken transversely through the upper end of the dog rocker and showing the parts as viewed from the front of the machine.

Fig. 5 is a detail, pe spective view of the bracket by which the feed pinion, escapement wheel and the shaft therefor are supported an the frame of the machine.

I have shown my invention embodied in the 1932. Serial No. 645,198

' f present instance in a No; 8 L. C. Smith typewriting machine in which the invention may be readily embodied without materially modifying the existing structural features thereof. It should be understood, however, that the invention is not no restricted to embodiment in any particular make of typewriting or like machine, or escapement mechanism therefor, but may be employed in such machines generally, wherever found available. 7

The present invention may be said to be in the ,a5 nature. of an improvement on a construction disclosed in a patent to Arthur W. SmithNo. 975,169, dated Nov. 8, 1910, although the construction of the present invention operates on a different principle from said patented structure.

In the accompanying drawing only so much of the L. C. Smith machine is disclosed as is neces-- sary to illustrate my invention in its embodiment therein.

The carriage (not shown) moves from side-toside of the machine over the top plate 1 and is spring impelled in the direction of its letter-feed movement in the usual manner. The carriage carries a feed rack 2 which meshes. with a feed pinion 3 and this pinion is fixed on one end of a shaft i that turns in a bearing member 5.- The opposite end of the shaft 4 has an escapement wheel 6 mounted thereon, which wheel, in the present instance, is fixed to the shaft by set screws 7 that are received in tapped openings in a hub 8 of the escapement wheel and bear at their inner ends against flat sides 9 on the escapement wheel shaft 4. g

A dog rocker, designated as a whole by the reference numeral 10, is, in the present instance, constructed as follows; a-housing at the upper end of the dog rocker receives a fixed feed dog 11 and a loose or stepping dog 12. The stepping dog is pivoted at 13 on one side of a sliding plate 1d received within the housing and adapted to slide longitudinally therein. A stop pin 15 extends laterally from one side of the plate 14 and coacts with a depending finger 16 on the stepping dog to limitthe motion thereof in one direction around its pivot 13, or up to its normal position 100 shown in the drawings. A spring 1'? is coiled around a laterally projecting pin 18 carried by the plate 14 and bears at one end 19 against a laterally projecting flange 20 on the plate 14. The other end of this spring bears upward against 105 the stepping dog 12 to normally hold it in its upper, effective, position. A depending projection 21 on the plate 14 coactswith a coiled ex,-v pansion spring 22 which is contained within a recess in the body portion of the dog rocker hous- 110 ing and bears at one end against the bottom wall 23 thereof. The force of this spring 22 is exerted to move the plate 14 to the left-hand end of its travel in the housing on the dog rocker, where it coacts with and is arrested by a stop pad 24. The movement of the plate 14 in the opposite direction is limited by a stop pad 25.

The construction and arrangement of the parts are such that a tooth 6 of the escapement wheel normally bears against the loose dog 12 as shown in Fig. i, and maintains the plate 14 at the righthand end of its travel against stop pad 25; the force exerted by the escapement wheel. on the loose dog overcoming the force of the spring 22. An actuation of the dog rocker on the depression of a printing key carries the stepping dog 12 out of the path of the engaged tooth 6 of the escapement wheel at the same time bringing the fixed dog 11 into the path thereof. When the stepping dog is thus released from the escapementwheel,

it is advanced to the left, as the parts appear in Fig. 4, under the power of the spring 22. As the dog rocker returns to normal position the holding or fixed dog 11 will be disengaged from the wheel and the stepping dog 12 in its advanced position will be brought into the path of the next oncoming tooth 6 of the escapement wheel, and will be engaged by it and forced to the Fig. 4 position, thereby advancing the carriage to the next single letter space position. The purpose of pivoting the stepping dog at I3 is to permit a reverse movement of the escapement wheel during the return of the carriage. each tooth on the escapement wheel will engage the rear bevel face 12 on the stepping dog and deflect said "dog downward against the force of its spring 17, thereby enabling the escapement wheel to receive a reverse rotation.

The construction as thus far described is, or may be, the same as that embodied in the No. 8 L. C. 'Smith machine.

In accordance with my present invention I mount the bearing 5 which carries the shaft 4, pinion 3v and escapement wheel '6 on a resilient bracket, or supportingmember designated as a whole by the reference numeral 26 and shown in detail in Fig. 5. This bracket comprises an upright central body portion 27 perforated at 23 to receive the stems of two headed screws 29 by which the bracket is fixedly secured to the'rear face of a depending portion 30 on thebearing 5. The bearing 5 and its depending member 30 are free from contact with the frame of the machine andreceive their sole support on the resilient bracket 26. The bracket 26 is provided with laterally projecting relatively narrow supporting arms Bland 32 which extend to a considerable distance at each side of he central supporting portion 27 of the bracket; The arm 31 is apertured at 33130 receive a headed screw 34 by which the outer end of said arm is fixedly secured to the usual depending plate 36 which constitutes a part of the frame of the machine and is secured to the top plate 1 thereof."

' 'A spacing washer 33 is received a countersunk opening in the rear of the plate '35 and is interposed between said plate and the bracket arm 31 to mainta n the latter spaced apart therefrom, as shot "Tig. 2. In a like manner the arm 32 is prov d with an aperture 36 that receives the stern of a headed clamping screw 37, the thread-ed end of which is received in a tapped opening inthe depending frame plate 35. A spacingwasher 36; corresponding to the washer 33,- is interposed between 'the'arni 32 and- At this time the rear face of the plate 35. Care should be exercised that the arms 31 and 32 should be firmly secured at their outer ends to the frame of the machine and that the central portion 27 of the bracket should be firmly secured to the depending member 30 in order to prevent any looseness that might result in a rattle between the parts or any undue yielding and yet provide sufficient resilience in the bracket to attain the desired results. The bracket 26 is preferably made of sheet metal and is of such a character as to yield very slightly when the carriage is arrested at the end of a letter space step. That is to say, at each drop of the carriage when it is arrested by the slide lcoacting with the padded stop 25, there is a shock or impact produced in arresting the full force of the carriage at this instant, and this shock ordinarily is transmitted to the frame of the machine and results in the production of considerable noise. However, in the present construction the resiliency of the bracket 26 is suff1- cient to absorb or counteract the shock and dissipate the vibrations within the bracket before they are transmitted to the part 35 and to the frame of the machine. This is sufilcient to ma terially reduce if not wholly eliminate the noise incidental to the feed of the carriage, without affecting the alignment of the printed characters. Obviously if the flexibility of the support for the escapement wheel and feed pinion is sufficient to enable the force of the carriage to materially overcome the resistance offered by the resilient supportand allow the parts to be thus maintained at the instant of impact of the type, then inaccurate spacing would result and improper alignment would follow, and the resilient support 26 accordingly made stiff enough not to yield to the blow so far as to cause bad spacing of the letters. However, in the present construction the resiliency of the bracket 26 is sufficient to absorb counteract or dissipate the shocks or impacts incident to the letter feed movements of the carriage before they reach the frame of the machine, thereby materially reducing or eliminating the noise Without, however, resulting in irregular letter spacing and a lack of alignment. It is, of course, therefore important that the degree of resiliency and flexibility should be sufficient for the purpose pointed out withouthaving a high degree of flexibility which would result in the irregular spacing indicated above. The extent of this resiliency and flexibility depends, of course, on various circumstances, such, for example, as the character and weight of the parts which the bracket 26 has to support. In practice I have found that the parts as shown are highly efiective for the attainment of the ends described, taking into consideration the fact that in all of the figures, except Fig. 5, the parts shown on a scale of two to one.

In addition to providing a resilient support for the escapement wheel and feed pinion, I prefer to employ a resiliently supported dog rocker for further providing against noise vibrationsbeing communicated from the dog rocker to the frame a of the machine. In the present instance the dog rocker 10 is the same as that employed in the No. 8 L. C. Smith machine except that the trunnions by which the dog rocker is pivotally supported have been cut away so that they are no longer used to support the dog rocker. Instead I provide a bracket or supporting member which, as shown, is cruciform in its shape and which is designated as a whole by the reference numeral I prefer to make this bracket 38 of resilient sheetmetal. Each of the upright arms. of this bracket 38 is forked at the outer end thereof so as to receive .the usual screws 39 and to underlie tively narrow and extends outwardly beyond the dog rocker where it terminates in an end portion 42, which extends at right angles to the body portion of its arm 41. These angular end portions 42 of the bracket are maintained out of contact with the dog rocker and are provided with bearing openings to receive the coned ends of pivot screws 43 which are threaded into tapped openings in rearwardly projecting arms 44 that project from the member 35.

The construction is such that there'is no free axial movement of the dog rocker on its supporting pivot screws 43. However, there is sufficient'flexibility in'the bracket 38 to counteract or prevent the shocks exerted on the dog rocker in the letter feed movements of the carriage from communicating noise vibrations to the frame of the machine, thus providing a further assurance of the reduction or elimination of noise incidental to the letter feed movements of the carriage.

Like the bracket 26 the degree of stiffness in the bracket 38 will depend somewhat on circum stances and may have to be varied somewhat depending on the structure in which it is employed, but the construction and arrangement of the parts as shown in the present instance provide the right amount of flexibility and resiliency in the bracket 38 to effectively reduce noise and yet provide accurate letter spacing.

While either the feed pinion etc. mounted as hereinbefore described, or the resilient mounting of the dog rocker in the manner indicated may in itself prove sufficient, they both, nevertheless, coordinate to most efiectively reduce or eliminate the noise that is ordinarily incident to the letter feed movements of the carriage, and in practice I'prefer to employ both arrangements, although as indicated above either may be used independently of the other at times.

It will be seen that by the provision of resilient means hereinbefore described any suitable escapement mechanism may be employed without modifying the existing structural features of the escapement devices per se and that there is no necessity for providinga special form of noiseless escapement devices per se in order to reduce the noise ordinarily produced during the operation of the carriage escapement mechanism.

It will be understood, moreover, that standard escapement devices now used on'the market may be readily employed for use of my invention in connection therewith.

In practice the extent of vibration in the resilient brackets 26 and 38 while slight, is nevertheless effective for the attainment of the ends pointed out and such mechanism in practice has proved as highly effective, if not more effective, toreduce noise of the carriage escapementrnechanism than where, in some instances, specially constructed noiseless escapement mechanisms have been employed.

In connection-with this invention it may be pointed out that theoretically when one metallic body of the dimensions of those here concerned has its motion arrested by collision with another,

there is always a yielding of one or both of the bodies and a reaction due to the resilience of the metal. In ordinary typewriter construction, a portion of this yielding is molecular in its nature and in its extent, and the collision causes a molecular vibration of the bodies, and the familiar metallic sound or noise. When one of the bodies either is the frame of the machine, or is in contact with the frame, the molecular vibrations are communicated to the frame, producing a noise the volume of which depends on the violence of the vibrationsand on the extent of surface which the vibrating metal exposes to the air. All these molecular vibrations are of great rapidity and of very minute amplitude.

In some efforts to eliminate or reduce the noise of typewriters, and, specifically, that produced by the carriage escapement, resort has been hadto resilient parts whose stiffness was so small that, on the arrest of the carriage at the end of its letter space step, there was a bodily yield to a material extent and a subsequent rebound which also was of material extent, that is to say, of an extent that'would cause a perceptible and objectionable variation in the spacing of the letters. Such vibrations are not only far longer than the molecular vibrations which cause noise but are also far slower. Some of these spring devices have reduced the noise, but have resulted .in irregular spacing of the letters.

In my construction the escapement wheel support and the dog rocker are connected with the frame of the machine only through the resilient members 26 and 38 respectively, which touch the frame only at their ends. These members have a stiffness which, at the arrest of the carriage, permits them to yield to an extentthat could be measured ,only with a micrometer, say perhaps some fraction of a thousandth of an inch. This is of an order of magnitude greater than that of the molecular vibrations above referred to and less than that of the spring devices heretofore employed to reduce noise. The devices of my invention are so mounted that theyhave a rate of vibration of their own, but such vibrations are much slower than the molecular vibrations; and they are therefore incapable of setting up those molecular vibrations in the frame. I On the other hand, compared with a letter-space step ofv the carriage, their vibrations have an amplitude that is minute; and compared with the period of time within:which it is possible to operate two type bars in succession, their period of vibration is extremely short. Therefore, the escapement neither makes a noise, nor does it result in noticeable irregularity of spacing.

While the construction of the present invention is very simple and inexpensive to manufacture, it is nevertheless highly effective in operation.

Various changes maybe made in the construc tion, and'features thereof may be'employed' without others, without departing from my invention as it is defined in the accompanying claims.

What I claim as new and desire to secure by Letters Patent: I 1 I 1; Carriage escapement mechanism for typewriting and like machines, comprising an escapement wheel and feed pinion, a machine frame,

and relatively resilient supporting means for said wheel and pinion interposed between the absorb or dissipate the shocks due to the arrest of the carriage in its successive step-by-step letter-space movements and thereby prevent the full force of such shocks from being transmitted to the frame of the machine and thus reduce the noise ordinarily incident thereto. I

2. Carriage escapement mechanism for typewriting and like machines, comprising an escapement wheel and feed pinion, a machine frame, and relatively resilient supporting means for said wheel and pinion interposed between the latter and the machineframe and effective to absorb or dissipate the shocks due to the arrest of the carriage in its successive step-by-step letter-space movements and thereby prevent the full force of such shocks from being transmitted to the frame of the machine and thus reduce the noise ordinarily incident thereto, said resilient supporting means being firmly connected to the frame of the machine and to the bearing for the escapement wheel and feed pinion.

3. Carriage escapement mechanism for typewriting and like machines, comprising an escapement wheel and feed pinion, a shaft on which said escapement wheel and feed pinion are supported, a bearing for said shaft, a machine frame, and a relatively resilient sheet metal supporting member interposed between and secured to the machine frame'and said bearing and constituting the sole support for said bearing, said supporting member being sufiiciently resilient to absorb or dissipate the shocks due to the arrest of the carriage in its successive step-by-step letter-space movements and thereby prevent the full force of such shocks from being transmitted to the frame of the machine and thus reduce the noise ordinarily incident thereto.

4;. Carriage escapement mechanism for typewriting and like machines, comprising an escapement wheel and feed pinion, a shaft on which said escapement wheel and feed pinion are supported, a hearing for said shaft, a machine frame, and a relatively resilient sheet metal supporting member interposed between and secured to the machine frame and said bearing and constituting the sole support for said bearing, said supporting member being inthe nature of a bracket having an upright central portion to which said bearing is connected and laterally projecting comparatively slender arms connected at the ends thereof to the frame ofthe machine, said bracket providing sufficient resilience to absorb or dissipate the shocks incident to the arrest of the carriage in its successive step-by-step letter-space movements and thereby prevent the full force of such shocks from being transmitted to the frame of the machine and thus reduce the noise ordinarily incident thereto.

' 5. Carriage escapement mechanism for typewriting and like machines, comprising a pivoted dog rocker, a frame of the machine, and a relatively resilient supporting bracket intermediate said frame and dog rocker and supportingthe latter at its pivotal axis against relative movement between the rocker and bracket axially of the dog rocker, said bracket being sufficiently resilient to absorb or dissipate the shocks incident to the arrest of the carriage in its successive step-by-step letter-space movements and thereby prevent the full force of such shocks from being transmitted to the frame of the machine and thus reduce the noise ordinarily incident thereto and without affecting the proper letter-space position of the carriage at each imprint.

6. Carriage escapement mechanism for typewriting and like machines, comprising a pivoted dog rocker, a frame of themachine, and a relatively resilient supporting bracket intermediate said frame and dog rocker and supportingthe latter at its pivotal axis against relative movement between the rocker. and bracket axially of the dog rocker, said bracket being suflicientlyresilient to absorb, or dissipate the shocks incident to the arrest of the carriage in its successive stepby-step letter-space movements and thereby prevent the full force of such shocks from being transmitted to the frame .of the machine and thus reduce the noise ordinarily incident thereto and without affecting the proper letter-space position of the carriage at each imprint, said bracket having a centrally disposed portion secured to the dog rocker and comparatively slenderlaterally extending arms with pivot bearings in the ends thereof.

'7. Carriage escapement mechanism for typewriting and like machines, comprising a pivoted dog rocker, a frame of the machine, and a relatively resilient supporting bracket intermediate said frame and dog. rocker and supportingthe latter at its pivotal axis against relative movement between the rocker and bracket axially of the dog rocker, said bracket being sufficiently resilient to absorb or dissipate the shocks incident to the arrest of the carriage in its successive step-by-step letter-space movements and thereby prevent the full force of such shocks from being transmitted to the frame of the machine and thus reduce the noise ordinarily incident thereto and without affecting the proper letterspace position of the carriage at each imprint, said bracket being made of sheet metal and cruciform in shape, the laterally extending arms of the bracket being comparatively slender and bent at their ends where they are provided with pivot bearings for cone pivot screws.

8. Carriage escapement mechanism for typewriting and like machines, comprising an escapement wheel and feed pinion, a machine'frame, relatively resilient supporting means for said wheel and pinion interposed between the latter and the machine frame and effective to absorb or dissipate the shocks due to the arrest of the car'- riage in its successive step-by-step letter-space movements and thereby prevent the full force of such shocks from being transmitted to the frame of the machine and thus reduce the noise ordinarily incident thereto, a pivoted dog rocker, and. a relatively resilient supporting bracket intermediate said frame and dog rocker and supporting the latter at its pivotal axis against relative axial movement between the rocker and .bracket.-

9. Carriage escapement mechanism for typewriting andlike machines, eomprisinga'n escap ment wheel and feed pinion, a shaft'on which said escapement wheel and feed pinion are supportedabearing for said shaft, av machine frame, a relatively resilient sheet metal supporting member interposed between and secured to the machine frame and said bearing, and constituting the'sole support for said bearing, said supporting member being sufficiently resilient to absorb or dissipate the shocks due to the arrest of the car riage in. its successive step-by-step:letter space movements and thereby prevent the full force of such shocks from being transmitted tothe frame of the machine and thus reduce the noise ordinarily incident thereto, a pivoted dog rockerya'nd a relatively resilient sheet metal supporting bracket intermediate said frame and dog rocker and supporting the latter at its pivotal axis, said supporting bracket being sufiiciently resilient to absorb or dissipate the shocks incident to the arrest of the carriage in its successive step-by-step letter feed movements.

l0. Carriage escapement mechanism for typewriting and like machines, comprising an escapement wheel and feed pinion, a shaft on which said escapement wheel and feed pinion are supported, a bearing for said shaft, a machine frame, a relatively resilient sheet metal supporting member interposed between and secured to the machine frame and said bearing and constituting the sole support for said bearing, said supporting member being sufficiently resilient to absorb or dissipate the shocks due to the arrest of the carriage in its successive step-by-step letterspace movements and thereby prevent the full fcrce of such shocks from being transmitted to the frame of the machine and thus reduce the noise ordinarily incident thereto, a pivoted dog rocker, and a relatively resilient sheet metal sup-- porting bracket intermediate said frame and dog rocker and supporting the latter at its pivotal axis, said supporting bracket being sufficiently resilient to absorb or dissipate the shocks incident to the arrest of the carriage in its successive stepby-step letter feed movements, said bracket having a centrally disposed portion secured to the dog rocker and comparatively slender laterally extending arms with pivot bearings in the ends thereof. 7

11. Carriage escapement mechanism for type- Writing and like machines, comprising an escapement wheel and feed pinion, a shaft on which said escapement wheel and feed pinion are supported, a bearing for said shaft, a machine frame, a relatively resilient sheet metal supporting member interposed between and secured to the machine frame and said bearing and constituting the sole support for said bearing, said supporting member being sufiiciently resilient to absorb or dissipate the shocks due to the arrest of the carriage in its successive step-by-step letter-space movements and thereby prevent the full force of such shocks from being transmitted to the frame of the machine and thus reduce the noise ordinarily incident thereto, a pivoted dog rocker, and a relative-- 1y resilient sheet metal supporting bracket intermediate said frame and dog rocker and supporting the latter at its pivotal axis said supporting bracket being sufficiently resilient to absorb or dissipate the shocks incident to the arrest of the carriage in its successive step-by-step letter feed movements, said bracket having a centrally disposed portion secured to the dog rocker and comparatively slender laterally extending arms, said bracket being made of sheet metal and cruciform in shape, the laterally extending arms of the bracket being bent at their ends where they are provided with pivot bearings for cone pivot screws.

GEORGE G. GOING. 

